"blue dye-stuff obtained from certain lichens," early 14c., from Middle Dutch lijkmoes (Dutch lakmoes), from lac (see lac) + moes "pulp." Another theory is that it represents Old Norse litmose, literally "lichen for dying," from Old Norse lita "to dye, to stain," from litr "color, dye" (see lit (n.1)) + mos "moss." Yet another idea connects the first element to Middle Dutch leken "to drip, leak" (see leak (v.)).
Whichever was the original word, it probably was influenced by the others. The dye is obtained from certain lichens. It is naturally blue but turns red in acid and is restored to blue by alkalis. Figurative use of litmus test is first attested 1957, from scientific use of litmus-treated paper as a chemical indicator. Litmus paper with this meaning is from 1803.
雙語例句
1. The success of wind power represents a litmus test for renewable energy.
風能作為動力的成功是對可再生能源一次立見分曉的檢驗。
來自柯林斯例句
2. The outcome will be seen as a litmus test of government concern for conservation issues.
這結(jié)果將被視為檢驗政府是否關(guān)注自然資源保護問題的試金石。
來自《權(quán)威詞典》
3. Ending the fighting must be the absolute priority, the litmus test of the agreements' validity.
停火絕對是第一要務(wù)，也是檢驗協(xié)議是否有效的試金石。
來自柯林斯例句
4. Litmus paper can be used as an indicator of the presence of acid in a solution.
石蕊試紙可用以測試溶液是否含酸.
來自辭典例句
5. Her litmus test for good breeding is whether you split infinitives.